Lymphatic System and Immunity Flashcards
Exam 2
What are the functions of the Lymphatic System?
- drain excessive ECF
- transport dietary fats
- defense
- return leaked plasma proteins to the blood
Resistance
the ability to ward off the pathogens that produce disease
What is lack of resistance called?
Susceptibility
What are the 2 areas of disease resistance?
Provide Definitions
- Nonspecific Resistance: includes defense mechanisms that provide general protection against invasion by a wide range of pathogens
- Immunity: involves activation of specific lymphocytes that combat a particular pathogen or other foreign substance
Extracellular Fluid
fluid surrounding the cell
How does swelling occur in the body?
excess ECF fluid not drained
Edema
- swelling that is cold to the touch
- cell retains normal size
Inflammation
- swelling that is warm to the touch
- cell are larger than normal
What 2 components make up the Extracellular Matrix?
- extracellular fluid
- fibers
Lacteal
special lymphatic vessel (capillary) where all dietary lipids are absorbed and delievrs chyle to the blood
Chyle
milky-white, fatty lymph
Why do lipids bypass the liver?
they are sticky
Lipoproteins
Definition and Name Them
lipid carriers in the blood
- Chylomicrons
- High Density Lipoprotein (HDL)
- Low Density Lipoprotein (LDL)
- Very Low Density Lipoprotein (VLDL)
Name the cells of the Lymphatic System
- Macrophages
- Lymphocytes (B & T)
Macrophages are basically…
fused monocytes
Where are Macrophages found?
in the ECM
Vasodilation
increase in the diameter of lumen of the blood vessel
What is lymph composed of?
- dead tissue cells
- dead leukocytes
- bacteria
- dietary fats
What color is lymph and why?
milky due to dietary fats
What are the Vessels of the Lymphatic System?
- Lymph Capillary
- Lymph Node
- Lymph Trunks
- Cisterna Chyli (AKA Confluence Capillary)
- Lymph Ducts (2)
The Path Lymph Flows
lypmh capillaries -> collecting lymphatic vessels -> lymphatic trunks -> lymphatic ducts
Lymph Capillary
- starting location for lymph transport
- weave between tissue cells and blood capillaries
- found throughout the body except in avascular tissue, the CNS, portions of the spleen, and red bone marrow
Lacteal
- a lymphatic capillary in the villus of the small intestine
- where all dietary lipids are absorbed
How do Lymph Capillaries differ from Blood Capillaries?
- have slightly larger diameter
- Can take up larger molecules (ex: proteins, cell debris, pathogens, cancer cells)
- collagen fibers anchored to matrix and one-way minivalves increase permeability
Collecting Lymphatic Vessels
- receive fluid from lymph capillaries
- consist of collecting vessels, trunks, and ducts
How to Collecting Lymphatic Vessels differ from Veins?
- thinner walls
- more internal valves
- anastomose more (joining together)
Lymphatic Trunks
- drain large areas of body
- formed by union of largest collecting vessels
List the principal lymphatic trunks
And how are they formed?
- paired lumbar trunks
- paired bronchomediastinal trunks
- paired subclavian trunks
- paired jugular trunks
- single intestinal trunk
Formed from the exiting vessels of lymph nodes
Lymphatic Ducts
- receive lymph from the lymphatic trunks
- empties lymph into venous circulation at respective junction of internal jugular and subclavian veins
Name the 2 Lymph Ducts
- Right Lymphatic Duct
-Thoracic Duct
Thoracic Duct
- main collecting duct of the lymphatic system
- begins as the cisterna chyli
What regions do the Thoracic Duct drain lymph from?
Where does is drian lymph into?
- left head region
- left neck region
- left thoracic region
- left arm region
- other areas below diaphragm
drains into venous blood via the left subclavian vein
What regions do the Lymphatic Duct drain lypmh from?
Where does is drian lymph into?
- right head region
- right neck region
- right thoracic region
- right arm region
drains into venous blood via the right subclavian vein
Lymphedema
severe localized edema caused by anything that prevents the normal return of lymph to the blood
ex: tumor blocking the lymphatics
ex: lymphatics removed during cancer surgery
Layers of the Lymphatic Vessel
only 1 layer - endothelium
attached to basement membrane
Name the Encapsulated Organs of the Lymphatic System
- spleen
- lymph node
- bone marrow
- MALT (Mucosa-Associated Lymphoid Tissue)
- Peyer Patches
- Thymus Gland
Name the Uncapsulated Organs of the Lymphatic System
- appendix
- tonsils (adenoid/pharingeal; palatine; linguinal)
Primary lymphatic organs
the red bone marrow and the thymus gland that produces and matures B and T cells
Secondary lymphatic organs
areas where mature lymphocytes first encounter their antigen and become activated
- lymph nodes
- spleen
- MALT (mucosa-associated lymphoid tissue) that form tonsils and diffuse lymphoid tissues
most immune responses are in secondary lymphatic organs
Lymphatic nodules
clusters of lymphocytes that stand guard in all mucous membranes
Where does interstitial fluid drain into?
lymph capillaries
List the passage of lymph
arteries -> blood capillaries (blood) -> interstitial spaces (fluid) -> lymph capillaries (lymph) -> lymphatic vessels -> lymph trunks -> thoracic OR right lymphatic duct -> subclavian veins (blood)
What does lymph flow as a result of?
- the milking action of skeletal muscle contractions and respiratory movements
- also aided by lymphatic vessel valves that prevent backflow of lymph
Thymus Gland
- lies between the sternum and the heart
- secrete Thymosin (endocrine)
- site of lymphocyte maturation, teaching them to become T-cells (lymphatic)
- large in the infant and after puberty is replaced by adipose and areolar connective tissue
Lymph nodes
- encapsulated oval structures located along lymphatic vessels
- contain T cells, macrophages, follicular dendritic cells, B cells
- site of proliferation of plasma cells and T cells